Pressure relief apparatus for potato dough extruder

ABSTRACT

A potato dough extruder incorporating an incremental manually operable pressure apparatus for manually extruding potato dough through an extrusion die which forms the dough into the shape of french fried potatoes, in which the potato dough is contained in a cylindrical container and pressure is applied to a pressure piston in the cylinder through a smooth cylindrical pressure shaft, the incremental pressure apparatus incorporating a ringlike gripping device which is slidable up and down the shaft so long as the ring is located in a plane substantially normal to the shaft, and in which the ring gripping device is tiltable out of such a plane and grasps the shaft at any point along its length thereby doing away with teeth, sprockets, and notched gripping devices and at the same time incorporating the improvement that as soon as the tilting force applied to the ring gripping device is released the pressure on the pressure shaft is also released. This particular improvement eliminates the tendency for the extrusion of the dough to continue after a single serving of french fries has been obtained from the machine.

United States atent Ilines [451 Apr. 10, 1973 PRESSURE RELEF APPTUS FORPOTATO DOUGH EXTRUDER Laurence James llines, 7 Feldbar Court,Willowdale, Ontario, Canada Filed: Aug. 17, 1970 Appl. No.: 64,357

Inventor:

Related US. Application Data Continuation-in-part-of Ser. No. 819,801,April 28, 1969, abandoned.

US. Cl. ..74/14l.5, 425/192, 254/106, 100/293 Int. Cl. .....F16h 27/02,Fl6h 31/00 Field of Search ..107/14 R, 14 B, 14 BA, 107/14 D, 14 DA, 1R, 69, 54 R; 17/35-40; 18/12 R, 12 P, 13 R, 13 D, 14 R, 30 FN, 30 OD;25/8, 11-20; 31/8, 13, 14,46; 100/291, 293, 57; 74/531, 107

References Cited UNITED STATES PATENTS 3/1970 llines ..107/14 R 10/1967Ilines 8/1969 Keil 9/ 1957 James 1 1/ 1960 Cadwellader 10/1916 Straub4/1967 Braselmann ..74/531 X Ill 3,045,499 7/1962 Dale ..74/531 XPrimary Examiner-Jordan Franklin Assistant Examiner-G. V. LarkinAttorney-George A. Rolston 57 ABSTRACT A potato dough extruderincorporating an incremental manually operable pressure apparatus formanually extruding potato dough through an extrusion die which forms thedough into the shape of french fried potatoes, in which the potato doughis contained in a cylindrical container and pressure is applied to apressure piston in the cylinder through a smooth cylindrical pressureshaft, the incremental pressure apparatus incorporating a ring-likegripping device which is slidable up and down the shaft so long as thering is located in a plane substantially normal to the shaft,

and in which the ring gripping device is tiltable out of such a planeand grasps the shaft at any point along its length thereby doing awaywith teeth, sprockets, and notched gripping devices and at the same timeincorporating the improvement that as soon as the tilting force appliedto the ring gripping device is released the pressure on the pressureshaft is also released. This particular improvement eliminates thetendency for the extrusion of the dough to continue after a singleserving of french fries has been obtained from the machine.

11 Claims, 6 Drawing Figures PAIENIED 3,726,149 SHEET 1 OF 3 I N VENT OKLAURENCE J. ILI NES l /xm PATENTED APR 1 0 973 SHEET 2 BF 3 INVENTOR.LAURENCE J. lLINE S PATENTEDAFR] 01975 SHiU 3 OF 3 LAURENCE J. ILINESPRESSURE RELIEF APPARATUS FOR POTATO DOUGH EXTRUDER The inventionrelates to a potato dough extruder incorporating a pressure shaftactuating means having built-in pressure relief capability. The presentapplication is a continuation in part of my co-pending application, Ser.No. 819,801 filed Apr. 28, 1969, now abandoned.

Potato dough extruders are known in the art of food product conversionmachines, examples being US. Pat. No. 3,344,752, Canadian Letters Patent548,824, and there are many other examples in the patent art of foodproduct extrusion devices for use in association with other types offood products. Such machines generally comprise a cylindrical barrel, anextrusion die at the lower end, and a pressure plate at the upper end.Some form of pressure shaft engages the pressure plate and a shaftactuating means is provided for forcing the shaft downwardly to extrudethe contents of the cylindrical container. Various different shaftoperating mechanisms have been proposed in the art, but they all exhibitvarious different disadvantages for the particular operation ofextruding potato dough. In the first place, apparatus of this kind isused by almost totally unskilled labour at drive-in restaurants and thelike, and its operation must therefore be of the utmost simplicity andcompletely fool proof, even when it is deliberately abused. Secondly,the apparatus must be such that it can be manufactured economically on amass production basis so that the machines can be installed in a largenumber of drive-ins, at a cost which is sufficiently low to permit theowner of the restaurant'to purchase the machine, and still realize asaving in the over-all cost of his operation, by being enabled to usepowdered potato dough for making french fried potatoes, in place ofemploying hand labour to peel the potatoes. The operation of theextruder develops 'very substantial pressures in the cylinder, and it isnecessary, in the construction of such an apparatus that the system formoving the pressure shaft should provide the operator with a verysubstantial mechanical advantage, in order to reduce the physical effortrequired to extrude individual servings of french fried potatoes. Withthe assistance of such a highly efficient manual drive system, it isquite common for breakages to occur in the equipment when it is operatedby unskilled personnel. For example, when the plunger or piston reachesthe bottom of the cylinder, there is invariably a small quantity ofpotato dough left which cannot be extruded. However, the operator of themachine will invariably attempt to obtain one or more extra servings byapplying extra pressure, with the result that the extrusion die issometimes broken, or the die becomes separated from the bottom of thecylinder, or the pressure shaft in some cases damages the plunger. Afurther, although somewhat less serious defect of the prior artmechanism is what may be called the tooth paste tube effect." Thus theapparatus is required to extrude a single serving of french friedpotatoes which are then cut off at the bottom of the extrusion die andcooked. Preferably, no further potato dough should be extruded aftercutting off of the one serving required. However, due to the design ofthe prior art type shaft actuating systems, the plunger or pressureplate within the cylinder continues to exert a certain residual pressureon the dough within the cylinder, and small quantities of dough willcontinue to' be extruded from the cylinder after the individual portionhas been cut off, somewhat in the manner in which tooth paste willcontinue to emerge from a tube after the finger pressure has beenremoved. This causes a certain minor degree of wasteage of potato dough,but, more seriously, the residual portions of dough will hang beneaththe extruding die and dry out and crumble. It is then necessary to cutoff such residual portions-of dough prior to extruding the next serving,thereby wasting time and effort.

The present invention is directed to overcoming these various problems,by providing a shaft actuating system which engages the shaft in africtional grip, rather than by means of a positive engagement such asis provided by teeth or a rack and pinion, and in which the frictionalgrip is released at the end of each stroke, thereby relieving thepressure. Such a system has a two fold advantage that it is impossiblefor the pressure in the container to build up between strokes of theactuating mechanism, and it is therefore impossible to overload theinterior of the container and cause damage, and in addition, theso-called tooth paste tube effect is avoided, since the pressure isautomatically relieved at the end of each stroke.

More specifically, it is an objective of the present invention toprovide a potato dough extruding machine incorporating pressure shaftactuating means providing a great mechanical advantage for the operator,and being capable of operation by a semi-rotary movement of an operatinglever, in an upward and downward direction and incorporating shaftengagement means adapted to engage the shaft at the upper end of thestroke, and to release the shaft at the lower end of the stroke.

The foregoing and other advantages will become apparent from thefollowing description of a preferred embodiment of the invention whichis given here by way of example only with reference to the followingdrawings in which like reference devices refer to like parts thereofthroughout the various views and diagrams and in which;

FIG. 1 is an upper perspective illustration of a potato dough extrudingmachine partially cut away to show the pressure shaft actuating meansaccording to the invention;

FIG. 2 is an exploded cut away perspective view of the pressure shaftactuating means seen from a point above and to the rear of FIG. 1;

FIG. 3 is a sectional side elevational view along the line 3-3 of FIG.1, and showing the actuating means in a lower position; I

FIG. 4 shows a perspective cut-away illustration of a further embodimentof the invention;

FIG. 5 is an enlarged perspective illustration of a detail of theembodiment of FIG. 4; and I FIG. 6 is an enlarged section along the line6-6 of FIG. 4 with a portion thereof shown in phantom.

Referring now to FIG. 1, it will be noted that this drawing shows apotato dough extruder having an upper star-shaped mounting frame 5provided with two forwardly directed arms 6 and a rearward arm 7 whichis of hollow cast construction, meeting at a central hub 8. Rear arm 7is provided with a connection flange 9 and hub 8 is also hollow and iscentrally bored as at 10 for purposes to be described below. A lowermounting plate 11 is connected below frame 5 by support rod means 12extending between arms 6 and 7 of frame 5 and lower mounting plate 1 1.

A base plate B is provided with an upstanding column C and the entireextruder is adjustably supported thereon by cantilever arm 13 connectedto flange 9 of rear arm 7 by bolts 13A and having a sliding collar 14riding on column C secured by set screw 15.

A removable cylindrical container 16 is located seated on ring 11, andring 11 is provided with a central opening (not shown) supporting anextruding die (not shown) having a series of extrusion openings thereinfor forming dough into suitably shaped french fried potatoes. Beneathring 11 is a cut off unit (not shown) operated by a cut off handle 17,the function of which is to cut off the lengths of dough after they areextruded. Within the container 16 is provided a plunger member 18,operated by a pressure shaft 19. The precise details of the foregoingfeatures are omitted from this description for the sake of clarity andit is believed that sufficient information can be obtained by referenceto one or other of the prior art patents referred to above. As stated,the potato dough which is located within the cylinder 16 is extruded bymeans of pressure applied through the plunger 18, which is in turnoperated by the pressure shaft 19. In certain prior art machines,provisions have been made for mechanically moving shaft 19 bothdownwardly and upwardly. However, in the present invention, this hasbeen simplified by providing a mechanical means for forcing the shaft 19downwardly, upward movement being achieved by hand, by means of graspingthe handle or knob 20 and drawing the shaft 19 upwardly. It willtherefore be understood that the pressure shaft actuating means now tobe described operates only to force the shaft 19 and plate 18downwardly.

The shaft actuating means according to the invention is indicated by thegeneral reference arrow 30. It will be seen to be located substantiallywithin the interior of the hollow cast rearward arm 7 and central hub 8.Access is provided to the hollow interior of rearward arm 7 through anopening 31 provided in connection flange 9, which is of course concealedand closed by cantilever arm 13.

Referring now to FIGS. 2 and 3 the shaft actuating means is there shownto comprise a plate-shaped lever member 32 having a central opening 33formed therethrough of a diameter somewhat greater than the diameter ofpressure shaft 19 whereby to permit lever member 32 to rock relative tothe axis of shaft 19 without contacting the same. Opening 33 is upwardlycounterbored as at 34 for approximately one half of the thickness oflever member 32, and within counterbore 34 there is provided a hardenedsteel gripping ring 35. Ring 35 has an interior diameter less than thediameter of opening 33, but slightly oversize in relation to thediameter of shaft 19 whereby to permit ring 35 to slide on shaft 19, butbeing sufficiently close to the diameter of shaft 19 whereby to grip andfrictionally engage shaft 19 when lever 32 is rocked out of a planenormal to the axis of shaft 19. It will be noted that opening 33 isprovided towards one end of lever member 32, and at the opposite end oflever 32 a roller cam follower 36 is rotatably mounted in any suitablemanner such as in the rectangular notch 37. Lever member 32 isdimensioned in relation to the interior dimensions of the hollowrearward arm 7, whereby to provide a loose degree of engagement betweenthe side edges 38 of lever member 32, and the interior opposed sidewalls 39 within arm 7, whereby to guide the upward and downward movementof lever member 32.

It will be understood from the foregoing that lever member 32 is movableboth in a rocking motion, from a normally horizontal position to aslightly angled position, relative to the axis of shaft 19, and is alsomovable, within the confines of the interior of hub 8 and rear arm 7,between upper and lower positions. In order to locate the lever member32 normally in the upper position, a compression spring 40 is provided,located around shaft 19, and extending between the lower wall 41 of hubmember 8 and the counter bore 34 of lever member 32. For purposes to bedescribed below, it is desirable that the upper position of lever member32 should be capable of being adjustably located, and for this purpose,a bearing sleeve member 42, externally threaded, so as to engage theinternally threaded axial bore 10 in the upper portion of hub 8, isprovided, having an upper knurled ring 43 for manual rotation thereof,and having a lower end 44 adapted to engage the upper member 32 anddefine an upward limit of movement. A lower bearing sleeve 42a is alsoprovided in the lower wall 41.

In order to both rock lever member 32 out of its nor mal horizontalposition, and also to drive lever 32 downwardly, under a substantialmechanical advantage, there is provided a substantially cylindrical cammember 45 excentrically mounted on a cam operating shaft 46, with cammember 45 in engagement with follower member 36 of lever member 32.Journal bearings 47 are formed integrally with rear arm 7 to locateshaft 46, and cam member 45 is fastened to shaft operating arm 49 isattached to the free end of shaft 46,

and is provided with a handle 50 by means of which lever 49 may begrasped and drawn forwardly towards the front of the machine.

In operation, the operator fills the cylindrical container 16 with asuitable quantity of potato dough formed of a mixture of potato flourand water in a well known manner, and the cylinder 16 is placed intoposition and the plunger 18 is introduced into the upper end of cylinder16. Plunger member 18 may then be pushed downwardly into the container16 by hand pressure applied to knob 20 at the upper end of shaft 19,until such time as plunger 18 engages the upper surface of the potatodough. At this point, further movement under simple hand pressure willbecome impossible. The machine is then ready for use to extrude dough inthe form of french fried potatoes. When it is desired to extrude aserving of such french fried potatoes, the operator simply grasps theknob 50 of handle 49 and draws handle 49 forwardly and downwardlytowards him. Such movement produces a semi-rotary movement of shaft 46and cam 45 attached thereto. Such movement of cam 45 will then firstcause lever member 32, through the engagement of cam follower 36, totilt out of its normal horizontal position. As lever member 32 tilts thehardened steel ring 35 will bite into thesurother form of limit settingdevice could be included. At

this point, the operator merely releases handle 50, and the force storedin compression spring 40 will cause lever member 32 to move upwardlythereby causing cam 45 to-rotate in the reverse direction and raiseoperating arm 49 and handle 50 to its upper position once more. Atthesame time it will be understood that the moment spring 40 commences toraise lever member 32, the grip applied by hardened steel ring 35 toshaft 19 is released, thereby immediately releasing the pressuregenerated within the container 16. In fact in many cases, it will befound that plunger 18 and shaft 19 will rise very slightly to relievesuch pressure,

thereby materially assisting in the raising of lever tendency forfurther extrusion to take place through the die, after the cut off arm17 has been operated.

In order to regulate the length of the portions of dough which areextruded on each stroke of operating arm 49, all that is required is forthe operator to merely grasp the knurled portion 43 of bearing sleeve 42and rotate it either upwardly or downwardly. Clearly upward rotation ofsleeve 42 will cause lever member 32 to adopt a higher position therebyproviding it with a longer stroke and resulting in a somewhat greaterlength of french fried potato, and movement of sleeve member 42 in thereverse direction will of course shorten the extruded length of frenchfries.

When the contents of cylinder 16 are substantially exhausted, andplunger 18 has reached almost to the bottom of cylinder 16, the reducedportion 51 of shaft 19 will just have reached the region of the upperposition of lever member 32, the length of shaft 19 being measured toensure that this takes place at this point. The next time the operatingarm 49 is moved forwardly, lever member 32 will tilt as before, but thering member 35 will not be able to engage any portion of shaft 19, sincethe reduced portion 51 thereof is too small to be contacted by ring 35.Thus although lever member 32 will be moved by cam member 45 asdescribed above, it will not apply any downward force to shaft 19. Inthis way, complete safety of the operation of the machine is ensurednotwithstanding the hasty attempts of an operator to obtain-one lastserving of french fries from the machine before recharging container 16.I

Obviously, the charging of container 16 is a simple operation. The knob20 is grasped and the shaft 19 is drawn upwardly thereby raising plunger18 out of container 16 after which container 16 may be removed, washedout, and re-charged and the entire operation can then continue. In somecases, it may be desirable to provide some form of means for locking theshaft 19 in 1 the upper position thereby leaving both hands free toremove container 16. If such a locking means is considered desirable, itcan take the form of a device such as a clip member indicated in phantomas 52 on FIG. 1 may be provided, which can be applied to arm 49 and lockit in a lower position, thereby effectively holding shaft 19 againstdownward movement.

It will further be noted that the construction of the device andparticularly the shaft operating means involves a minimum of machinedparts and that the frame member 5 including arm 6, hub 8, and rear arm 7may all be cast in one piece, thereby materially reducing theconstruction costs. In addition, the assembly and disassembly of theentire mechanism can be performed substantially without any specialtools. All that is required is to release bolts 13A, after which accessmay be had to the interior of hollow arm 7. Thelever member 32 may beremoved and replaced by merely, for example, removing knob 20 from theupper end of shaft 19 after which shaft '19 may be drawn completely outof hub 8 thereby leaving lever member 32-free to be removed. Thustheonly part to be subjected t'oany very substantial wear may be regularlyservicedand maintained in good condition without any difficulty by theoperator of the machine itself.

According to a further embodiment of the invention shown in FIGS. 4, 5and 6, the design may be further improved and modified, by replacing thecam assembly 30, and the cam 45 by an improved cam assembly indicated inFIGS. 4 and 5 by the general reference 60, by means of which theentirecam assembly may be enclosed so as to prevent the accumulation offood particles, or the contamination of food, or soiling of theoperator's hand by machine lubricants or the like. 7

According to this preferred embodiment, a totally enclosed housing 61 isprovided having top and bottom walls 62 and 63, and an end closure plate64 removably attachable thereto by any suitable'screw means (not shown).The housing 61 of course, merely replaces the hollow arm portion 7 ofthe embodiment of FIG. 1, or alternatively may be provided with mountingflanges 65 on either side thereof, whereby the same may be mounted byscrews or bolts or the like on any other suitable supporting plate orarm performing the functional equivalent of the arm 13, the details ofwhich are not shown forthe sake of clarity. As in the case of theembodiments of FIGS. 1, 2, and 3, the pressure shaft 19 predeterminedthickness, having an oversized bore 67 (see FIG. 7) formed therethroughat a predetermined angle, preferably in the region of from 10 to 14 offthe perpendicular. The bore 67 should be sufficiently oversize inrelation to the diameter of the shaft 19, that the shaft 19 may slidefreely through the bore 67 when the bore 67 is aligned precisely withthe axis of the shaft 19. Such precise alignment will occur, of course,when the drive lever 66 is angled out of the horizontal, or in anyevent, is angled relative to the drive shaft 19 by an angle equal to theangulation between the axis of the bore 67 and the perpendicular to theplate 66. An end 68 of the drive lever 66 extends into contact with thecam rod device 69. The cam rod 69 extends between two oversize hubmembers 70, and is offset from the centres of the hub members 70 asshown. Hub mem- ,then drop under its own weight downwardly until bers 70are themselves rotatably mounted in the opposed side walls of thehousing 61 in the inset journal bearings 71, and the right-hand hubmember 70 is provided with an operating arm 72 fastened in the threadedrecess 73. The cam rod 69 is fastened in the hub members 70, by means ofthe pins 74 to prevent rotation thereof. Cam rod 69 is of cylindricalcross-section at each end, and in the intermediate portion thereof, itis cut away as at 75 and provided with a rounded bevelled edge 76, tominimize friction between the edge 76 and the extension portion 68 ofthe drive lever 66. As in the embodiment of FIGS. 1, 2 and 3, a spring40 is provided around shaft 19, to hold the drive lever 66 in its upperposition. In addition, in order to hold the drive lever 66 in itspredetermined angled position as shown in FIGS. 5 and 7, when in theupper position, a sliding collar member 77 is provided around shaft 19,having a lower bearing surface 78 cut at an angle corresponding to theangle in which it is intended that the lever member 66 shall lie when inits inoperative position. In this way, when the lever member 66 ispressed upwardly by the spring against the bearing surface 78, the levermember 66 will lie in the predetermined desired angular position,whereby to permit free sliding of shaft 19 upwardly and downwardly. Thesliding collar member 77 is formed in a rectangular or square shape asshown, and is dimensioned to fit loosely between the sides of thehousing 61, soas to prevent inadvertent rotation thereof in use.

Any suitable stop means such as the check rod 79 may be provided toprevent excessive movement of the handle 72 and the cam rod 69.

In operation, the drive lever 66 will normally be in its upwardly tiltedposition as shown in FIGS. 4 and 6, with the axis of bore 67 alignedwith the axis of shaft 19. In this position, the spring 40 is urging thedrive lever 66 upwardly against the lower bearing surface 78 with thesliding collar 77 which functions to hold the drive lever 66 at thedesired predetermined angle. As soon as the operator pulls the handle 72towards the front of the machine in an anti-clockwise direction, thehubs 70 rotate, and cause the cam rod 69 to move around an arc of acircle, bringing the bevelled edge 76 into contact with the extended endportion 68 of the drive lever 66. As the rotary movement is continued,the bevelled edge 76 will tilt the extension portion 68 of the levermember 66 downwardly, thereby bringing the edges of the lever member 66around the bore 67 into contact with the shaft 19. Continued rotationwill cause the bevelled edge 76 to move still further downwardly, andforce the entire lever member 66 and shaft 19 to move spring 40 willthen force the drive lever 66 into the upwardly tilted position again,thereby releasing the hold on the drive lever 66 on the shaft 19. Theshaft 19 will checked by contact of the pressure plate with the dough inthe cylinder. The operator may then make a further movement with thehandle 72 thereby extruding further dough.

In this form of the invention, it is found that the arrangement of thecam rod 69 and the bevelled edge 76 located towards the outercircumference of the hub members 70, provides a highly effective camaction in which the degree of leverage obtained between the handle 72and the axis of rotation of the hub members 70, and the point of contactbetween the bevelled edge 76 and the extension portion 68, becomesprogressively greater as the handle 72 is further depressed, therebyproviding an increasing degree of leverage as the pressure builds upwithin the cylinder.

The foregoing is a description of a preferred embodiment which is givenhereby way of example only. The invention is not to be taken as limitedto any of the specific features as described, but comprehends all suchvariations thereof as come within the scope of the appended claims.

What I claim is:

l. Incremental pressure apparatus for use in association with machinesfor extruding food product dough such as potato dough and the like ofthe type having upper and lower supporting members spaced apart andremovably receiving a dough receiving cylinder and extrusion dietherebetween, said cylinder incorporating a pressure piston, saidpressure apparatus comprising;

a housing associated with said upper supporting member of said machine;upper and lower openings in said housing arranged on a common verticalaxis; I pressure shaft means extending through said openings forapplication of pressure to said piston in said cylinder; releasablefrictional shaft gripping means extending around said shaft within saidhousing, said gripping means being normally oriented in a shaftreleasing position and being tiltable relative to the axis of said shaftto frictionally engage same, said gripping means being additionallymovable upwardly and downwardly on a substantially vertical path withinsaid housing between upper and lower positions,

and manually operable drive means mounted on said housing and engageablewith said gripping means and operable to first tilt the same into itssaid gripping position and then drive same downwardly along saidvertical path into its lower position, said gripping means returning toits upper position upon release of said drive means.

2. Incremental pressure apparatus as claimed in claim 1 wherein saidshaft gripping means incorporates a lever member of predetermined widthand length, the width being greater than the width of said pressureshaft, and the length being greater than the width, an opening formedthrough said lever member for reception of said pressure shaft meanstherethrough, and shaft engaging means associated with said levermember.

3. Incremental pressure apparatus as claimed in claim 1 including areduced neck portion at the upper end of said shaft means, said reducedneck portion being spaced from the lower end of said pressure shaftmeans a predetermined distance, whereby to bring said reduced neckportion into registration with said shaft gripping means to terminatefurther operation thereof at a terminal point just prior to engagementof said pressure piston with the lower end of said cylinder.

4. Incremental pressure apparatus as claimed in claim 1 includingbearing sleeve means mounted in said upper opening in said housing forslidably receiving said pressure shaft means therethrough.

5. Incremental pressure apparatus as claimed in claim 1 wherein saidshaft gripping means includes a lever member, an oversized openingformed through said lever for loosely receiving said pressure shafttherethrough; and a generally annular shaft engaging ring of hardmaterial mounted in said opening in said lever member, defining aninterior diameter less than that of said opening, and slidably receivingsaid shaft means therethrough.

6. Incremental pressure apparatus as claimed in claim 1 wherein saidmanually operable drive means includes a cam member, a shaft mountingsaid cam member in operable position and movable within said housing,and cam follower means associated with said shaft gripping means forengagement by said cam member.

7. Incremental pressure apparatus as claimed in claim 1 including ashaft for said manually operable drive means, shaft bearing means formedon said housing for rotatably receiving said shaft therein, and aneccentrically mounted drive member on said shaft, said drive memberbeing dimensioned and oriented to engage said shaft gripping means asaforesaid.

8. Incremental pressure apparatus as claimed in claim 1 including aspring normally urging said shaft gripping means upwardly within saidhousing, and adjustable stop means mounted in said housing for definingan upward limit of movement for said shaft gripping means.

9. Incremental pressure apparatus as claimed in claim 1, wherein saidshaft gripping means includes a lever member, an opening formed throughsaid lever member which is oversize with respect to the diameter of saidshaft, said opening being formed at a predetermined angle, whereby whenthe axis of said opening is aligned with the axis of said shaft, saidlever member will be tilted relative to the axis of said shaft.

10. Incremental pressure apparatus as claimed in claim 1, wherein saidshaft gripping means includes a lever member, tiltable between anon-operating position wherein the same is angled relative to the axisof said shaft, and an operating position tilted at a different a n le,and including sli ding collar means adapted to e on said shaft withinsaid housing, and having a r1 lower surface angled relative to the axisof said shaft, at an angle substantially equal to the angle of saidlever member when in its said non-operating position.

11. Incremental pressure apparatus as claimed in claim 1, wherein saidmanually operable drive means comprises oversize hub members mounted inopposite side walls of said housing for rotation in unison, cam rodmeans mounted between said hub members and offset with respect to thecentral axis thereof, and a contact surface formed on said cam rod meansfor contacting said frictional shaft gripping means.

1. Incremental pressure apparatus for use in association with machinesfor extruding food product dough such as potato dough and the like ofthe type having upper and lower supporting members spaced apart andremovably receiving a dough receiving cylinder and extrusion dietherebetween, said cylinder incorporating a pressure piston, saidpressure apparatus comprising; a housing associated with said uppersupporting member of said machine; upper and lower openings in saidhousing arranged on a common vertical axis; pressure shaft meansextending through said openings for application of pressure to saidpiston in said cylinder; releasable frictIonal shaft gripping meansextending around said shaft within said housing, said gripping meansbeing normally oriented in a shaft releasing position and being tiltablerelative to the axis of said shaft to frictionally engage same, saidgripping means being additionally movable upwardly and downwardly on asubstantially vertical path within said housing between upper and lowerpositions, and manually operable drive means mounted on said housing andengageable with said gripping means and operable to first tilt the sameinto its said gripping position and then drive same downwardly alongsaid vertical path into its lower position, said gripping meansreturning to its upper position upon release of said drive means. 2.Incremental pressure apparatus as claimed in claim 1 wherein said shaftgripping means incorporates a lever member of predetermined width andlength, the width being greater than the width of said pressure shaft,and the length being greater than the width, an opening formed throughsaid lever member for reception of said pressure shaft meanstherethrough, and shaft engaging means associated with said levermember.
 3. Incremental pressure apparatus as claimed in claim 1including a reduced neck portion at the upper end of said shaft means,said reduced neck portion being spaced from the lower end of saidpressure shaft means a predetermined distance, whereby to bring saidreduced neck portion into registration with said shaft gripping means toterminate further operation thereof at a terminal point just prior toengagement of said pressure piston with the lower end of said cylinder.4. Incremental pressure apparatus as claimed in claim 1 includingbearing sleeve means mounted in said upper opening in said housing forslidably receiving said pressure shaft means therethrough. 5.Incremental pressure apparatus as claimed in claim 1 wherein said shaftgripping means includes a lever member, an oversized opening formedthrough said lever for loosely receiving said pressure shafttherethrough; and a generally annular shaft engaging ring of hardmaterial mounted in said opening in said lever member, defining aninterior diameter less than that of said opening, and slidably receivingsaid shaft means therethrough.
 6. Incremental pressure apparatus asclaimed in claim 1 wherein said manually operable drive means includes acam member, a shaft mounting said cam member in operable position andmovable within said housing, and cam follower means associated with saidshaft gripping means for engagement by said cam member.
 7. Incrementalpressure apparatus as claimed in claim 1 including a shaft for saidmanually operable drive means, shaft bearing means formed on saidhousing for rotatably receiving said shaft therein, and an eccentricallymounted drive member on said shaft, said drive member being dimensionedand oriented to engage said shaft gripping means as aforesaid. 8.Incremental pressure apparatus as claimed in claim 1 including a springnormally urging said shaft gripping means upwardly within said housing,and adjustable stop means mounted in said housing for defining an upwardlimit of movement for said shaft gripping means.
 9. Incremental pressureapparatus as claimed in claim 1, wherein said shaft gripping meansincludes a lever member, an opening formed through said lever memberwhich is oversize with respect to the diameter of said shaft, saidopening being formed at a predetermined angle, whereby when the axis ofsaid opening is aligned with the axis of said shaft, said lever memberwill be tilted relative to the axis of said shaft.
 10. Incrementalpressure apparatus as claimed in claim 1, wherein said shaft grippingmeans includes a lever member, tiltable between a non-operating positionwherein the same is angled relative to the axis of said shaft, and anoperating position tilted at a different angle, and including slidingcollar means adapted to ride on said shaft within said housing, andhaving a lower surface angled relative tO the axis of said shaft, at anangle substantially equal to the angle of said lever member when in itssaid non-operating position.
 11. Incremental pressure apparatus asclaimed in claim 1, wherein said manually operable drive means comprisesoversize hub members mounted in opposite side walls of said housing forrotation in unison, cam rod means mounted between said hub members andoffset with respect to the central axis thereof, and a contact surfaceformed on said cam rod means for contacting said frictional shaftgripping means.